1. Field
Embodiments of this disclosure relate to packaged semiconductor devices. More particularly, this disclosure relates to devices and methods for reducing corrosion in wire bonds.
2. Related Art
Wire bonding is used in the semiconductor industry to form electrical connections between contact pads on an integrated circuit (IC) die and contact pads on a package substrate. Ball bonds are formed with one end of the wire on the contact pads of the IC die and wedge or stitch bonds are formed with the other end of the wire on the contact pads of the package substrate. Alternatively, wedge bonds can be used on both ends of the wire at the bond pad on the IC die and the bond pad on the package substrate.
In some instances, the wire is coated with one or more layers of a metal, ceramic and/or organic material that exhibit desirable characteristics such as promoting formation of a bond during the wire bonding process and improving reliability in air-to-air temperature cycling and high temperature bake. The coating can also help prevent corrosion of the wire when the packaged semiconductor device during assembly and when used in the field. A problem can arise if portions of the coating are removed during the bonding process thereby exposing the wire to potentially corrosive elements.